Ray, Mallar and Basu, T S and Jana, Arpita and Bandopadhyay, N R and Hossain, S M and Pramanick, A K and Kile, Robert F (2010) Luminescent core-shell nanostructures of silicon and silicon oxide: Nanodots and nanorods. Journal of Applied Physics, 107 (6). 064311.
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We report synthesis and luminescent characteristics of core-shell nanostructures of silicon and silicon oxide having two different morphologies—spherical (nanodot) and rodlike (nanorod), prepared by controlled oxidation of mechanically milled crystalline silicon and by exfoliation of the affected layer of porous silicon. Colloidal suspensions of these nanostructures exhibit intense room temperature photoluminescence (PL), detectable with the unaided eye. PL band peak energies of the colloidal suspensions formed from porous silicon are blue shifted by ∼ 1 eV compared to the as-prepared films on silicon substrate. In addition, PL spectra of all the colloidal suspensions blueshift with increase in excitation energy but the PL peaks of as-prepared porous silicon are independent of excitation. However, shape of the nanocrystals (spherical or rodlike) is found to have little effect on the emission spectra. These observations are explained in terms discretization of phonon density of states and electronic transitions involving surface defect states and quantum confinement induced widened band states.
|Uncontrolled Keywords:||Nanodots; nanorods; nanostructures; silicon oxide|
|Divisions:||Material Science and Technology|
|Deposited By:||Dr. A K Sahu|
|Deposited On:||26 Sep 2010 14:49|
|Last Modified:||08 Feb 2012 16:33|
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